How do I configure ISPconfig USING DMZ DNS server???

I have installed ISPconfig and installation was simple.
I like to use this box as webserver for several domains, but not for DNS server, I like to use my DNS server on the dmz, what do I need to do to make this work (if it works)?how do I set up my ISP box and my Main DNS box. I already have entery for the web. Do I have to create diffrent domains for my resellers on the main DNS sever and pint it to ISP box?

Please forgive me if this sounds confusing, because I am totaly confused

You dont have to use the DNS server on your ISPConfig server. Just configure your domains on the DNS server in the DMZ as usual and point the A-Records of your domains to the IP of your ISPConfig server.